Heath was a solid fighter who was one of the pioneers that were able to neutralize the big wrestlers on the ground and regain his feet.
The time he TKO'ed Erickson, Tom was considered a terror. An agile 290 lb wrestler who handled Randleman in the UFC like a father would handle an unruly child.
I think Herring was a handful for anybody. He could strike and survive on the ground against ground specialists. He wasn't quite the same guy later in his career, but was still good enough to remain at the elite level. He was using outdated techniques that got him by the other big guys in the past, but weren't working as well now. As far as the Lesnar fight goes, it doesn't really mean much to me. Brock has been taking supplements throughout his career.